A former soldier has admitted the manslaughter of four members of his family, who were found shot dead at the home they shared in Newcastle.
David Bradley, 41, was originally charged with the murders of his uncle Peter Purcell, aunt Josie, both 70, and their sons Keith, 44, and Glen, 41.
But those charges were dropped when it was found he was mentally ill.
The judge at Newcastle Crown Court ruled psychiatric reports be prepared and he remanded Bradley in custody.
Newcastle Crown Court heard how the bodies were found in Benwell Grove on 9 July 2006.
Bradley admitted the manslaughter charges on the grounds of diminished responsibility after two psychiatrists agreed he was mentally ill at the time of the killings.
Other medical experts, appearing for the prosecution and defence, also told the court the defendant was a heavy user of cannabis, which may have contributed to the deterioration in his mental health.
Detectives said the massacre happened because Bradley "flipped", began smashing up the house and then fought with his cousin Keith.
It resulted in Bradley killing his family over a five-hour period, on the night of 8 and 9 July, at their home in the West End of Newcastle.
Almost four hours after the killing spree, Bradley was caught on CCTV calmly walking the short distance to West Road Police Station carrying an arsenal of weapons in a rucksack.
The footage shows him pausing to stub out a cigarette before going into the station to give himself up.
The former Royal Artillery private, who served in the first Gulf War, Bosnia and Northern Ireland, shot father-of-six Peter and Keith immediately, before lying in wait for his aunt Josie and cousin Glen.
The court was told Bradley would need to be assessed by psychiatrists at Rampton secure hospital in Nottinghamshire.
Toby Hedworth QC, prosecuting, said two medical experts, for the Crown and the defence, agreed Bradley had suffered mental illness.
"Both of these eminent doctors are of the view that the defendant has suffered lifelong behavioural and emotional difficulties, which worsened following his 1995 discharge from the Army, he said.
The bodies of the family were found in their home
"His mental state deteriorated more acutely in 1997.
"They both agree at the time of the killings that the defendant was suffering from a mental disorder which constitutes an abnormality of the mind."
Mr Hedworth said the defence's expert believed Bradley was suffering post traumatic stress disorder (PTSD) after serving with the Army in Northern Ireland.
But both experts agreed that he did not suffer from Gulf War Syndrome, contrary to reports which appeared in the aftermath of the killings.
The court also heard that Bradley did not see any active service during his deployment to the Gulf.
'Jaded and weird'
Det Supt Steve Wade, who led the inquiry, spoke after the hearing about Bradley's state of mind before the killings.
"He said he had felt 'jaded and weird', the hot weather was getting to him and he had 'started to flip'," said Det Supt Wade.
A spokesman for Northumberland, Tyne and Wear NHS Trust said an independent inquiry into Bradley's care and treatment was to be carried out.
He said: "At this stage, pending the outcome of the independent inquiry, there is nothing further that we can add other than to offer our condolences to the families involved."
A further hearing will be held on 26 February.